Some containers for food products, such as cookies and other snacks, typically include an outer wrapper. In one type of container, the wrapper surrounds a frame which acts as a tray to hold the food product and to protect the food product from damage. Other food products come packaged in plastic trays, such as thermoform trays which are sealed on the top using some type of lidding material. One recent advancement in the art of food container closures includes a resealable closure disclosed in U.S. Pat. No. 6,918,532 (hereinafter “the '532 patent”), herein incorporated by reference, which discloses a wrapper which forms a top of the container, which has an access opening covered by a resealable sealing panel.
In the packaging art, different methods have been used to indicate whether a package has been previously opened or whether the integrity of the package has been compromised, which is often referred to in the art as “tamper-evident.” For example, in the tissue wipes packaging art of U.S. Pat. No. 6,428,867 (hereinafter “the '867 patent”), a means for indicating package integrity includes a tamper-evident tab with one or more ink layers which is initially an integral part of a sealing panel prior to the package being opened for a first time. The tab is transferred with one of the ink layers from the sealing panel to the top of the package when the closure has been opened for a first time. Tamper-evidence is indicated in a misalignment of the sealing panel with an image on the transferred tab, which is visible through a transparent outer layer of the sealing panel, after the sealing panel has been resealed to the top of the package.
There is a need for improvement in the art for package integrity indicators for a resealable closure, preferably suitable for use with a resealable closure for containers or packages containing food items.